Cloning and sequencing of four new mammalian monocarboxylate transporter (MCT) homologues confirms the existence of a transporter family with an ancient past
| Autor: | P. Andrew Halestrap, N. Vicky Jackson, T. Nigel Price |
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| Rok vydání: | 1998 |
| Předmět: |
Gene isoform
DNA Complementary Molecular Sequence Data ved/biology.organism_classification_rank.species Carboxylic Acids Biology Biochemistry Conserved sequence Animals Humans Amino Acid Sequence Cloning Molecular Molecular Biology Peptide sequence Caenorhabditis elegans Genetics Cloning Monocarboxylate transporter Sequence Homology Amino Acid cDNA library ved/biology Cell Membrane Sulfolobus solfataricus Cell Biology Blotting Northern biology.organism_classification biology.protein Carrier Proteins Research Article |
| Zdroj: | Biochemical Journal. 329:321-328 |
| ISSN: | 1470-8728 0264-6021 |
| Popis: | Measurement of monocarboxylate transport kinetics in a range of cell types has provided strong circumstantial evidence for a family of monocarboxylate transporters (MCTs). Two mammalian MCT isoforms (MCT1 and MCT2) and a chicken isoform (REMP or MCT3) have already been cloned, sequenced and expressed, and another MCT-like sequence (XPCT) has been identified. Here we report the identification of new human MCT homologues in the database of expression sequence tags and the cloning and sequencing of four new full-length MCT-like sequences from human cDNA libraries, which we have denoted MCT3, MCT4, MCT5 and MCT6. Northern blotting revealed a unique tissue distribution for the expression of mRNA for each of the seven putative MCT isoforms (MCT1-MCT6 and XPCT). All sequences were predicted to have 12 transmembrane (TM) helical domains with a large intracellular loop between TM6 and TM7. Multiple sequence alignments showed identities ranging from 20% to 55%, with the greatest conservation in the predicted TM regions and more variation in the C-terminal than the N-terminal region. Searching of additional sequence databases identified candidate MCT homologues from the yeast Saccharomyces cerevisiae, the nematode worm Caenorhabditis elegans and the archaebacterium Sulfolobus solfataricus. Together these sequences constitute a new family of transporters with some strongly conserved sequence motifs, the possible functions of which are discussed. |
| Databáze: | OpenAIRE |
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